# How Do You Know? - Asking Questions with the Hiding Game

Players: A parent and as many kids as you want!
Ages: 4-7
Cost: Free
Math Ideas: Commutativity, decomposition, number families
How do you know?

Commercial board games are great fun, but sometimes you just need a way to kill 10 minutes while dinner is cooking. In those situations, I like to pull out little games like the Hiding Game to start a conversation

## How to Play

All you need for this game is a set of similar objects - pennies, LEGO bricks, goldfish, or whatever you'd like.

The game is simple. You put out a set of blocks or goldfish and ask your child to count them. Then you ask her to close her eyes while you hide some of the blocks. When she opens her eyes you ask "How many did I hide?"

## Where's the Math?

The game is simple, but the mathematical ideas are not! By hiding some of the blocks, you've forced your child to find a quantity without being able to count it directly. If you started with six blocks and now your child can only see four, she has to think abstractly about the quantities of four and six in order to find the right answer.

Another idea that kids interact with in the game is the idea that two numbers add to the same sum, regardless of the order in which you add them. This is known as the commutative property of addition, and it seems utterly obvious to adults. If 3+2 is 5, then clearly 2+3 is also 5, right?

But kids don't know that yet. Just watch this video below of my son playing the Hiding Game with eight pieces.

Did you see that? When I take away two pieces, he gets the answer almost immediately. But when I leave those two and take the other six pieces, he sits and thinks for a full 30 seconds before getting the right answer. He needs to keep playing with this game to keep interacting with this concept.